Methods and apparatus for providing speech recognition services to communication system users

ABSTRACT

Methods and apparatus for providing speech recognition capability to callers in a cost efficient manner as part of one or more telephone services are described. Multiple speech recognition units with differing capabilities and therefore implementation costs are provided. Calls are assigned to speech recognition circuits throughout a call based on a signal such as a service type identifier indicating the type of service to be provided to the caller. During different phases of a call different speech recognition units may be used. In addition, different amounts of speech recognition processing capability may be allocated to service a call at different points during a call. In this manner efficient use of available speech recognition resources can be achieved.

RELATED APPLICATIONS

The present application is a continuation of pending allowed U.S. patentapplication Ser. No. 09/082,553 which was filed on May 21, 1998 andwhich issued on May 8, 2001 as U.S. Pat. No. 6,229,880.

FIELD OF THE INVENTION

The present invention is directed to communications systems and, moreparticularly, to methods and apparatus for increasing the utility andinteroperability of peripheral devices, e.g., voice mail devices andspeech recognition platforms, used in communications systems.

BACKGROUND OF THE INVENTION

In telephone systems, electronic switches are used to route calls totheir destination, e.g., as designated by a destination telephonenumber. They are also used to connect telephone service subscribers tovarious peripheral devices, such as, e.g., voice messaging systems (alsosometimes referred to as voice mail systems), speech recognizers, voicedialing services, etc. Peripheral devices are usually provided with somedegree of intelligence, e.g., logic in the form of a CPU, so that thesubscriber and peripheral device can communicate in an interactivefashion and/or to enable the peripheral device to interact with theswitch in a meaningful way. Peripheral devices with such built inintelligence are frequently referred to as intelligent peripherals or“IPs”.

FIG. 1 illustrates a known telephone system 100 which supports voicemail services. The known system 100 includes first and second telephonenetworks 10, 11 coupled together by a fiber optic connection 32. Each ofthe telephone networks 10, 11 includes a plurality of telephones 12, 14,a central office (C.O.) switch 16 and first and second voice mail IPs28, 30. As illustrated the switch 16 includes first and secondinterfaces 18, 24, a central processing unit (CPU) 20, memory 22 anddigit receiver 26. As discussed below, the C.O. switch 16 is capable ofconnecting a telephone to a voice mail IP 28, 30 or one of the othertelephones 12, 14. The central office switch 16 is coupled to each voicemail IP 28, 30 by a T1 link and a simplified message desk interface(SMDI) connection. The voice mail IPs 28, 30 can indicate to the centraloffice switch 16 that a message is waiting for a particular subscriberand that the subscriber's message waiting light should be activated inthe event that the particular subscriber's telephone 12, 14 includesmessage waiting light functionality.

One common technique for providing telephone service subscribers accessto an IP, which provides a desired service, involves the subscriberdialing a telephone number corresponding to the IP. For example, when asubscriber to a voice mail service desires to check for receivedmessages in one known system the subscriber would normally dial atelephone number corresponding to the subscriber's voice mail service.In response to detecting the telephone number corresponding to the voicemail IP, the C.O. switch 16 couples the voice mail subscriber to thevoice mail IP 28 or 30 as indicated by the dialed telephone number. Inaddition to dialing the telephone number of the voice mail service, asubscriber may also have to enter into the telephone, e.g., bydepressing a series of keys, account number and/or a personalidentification number (PIN) required by the voice mail IP to gain accessto the subscriber's account.

In the case of multi-party mail box accounts, once access to a voicemail account is obtained, the mail service may request that thesubscriber depress one or more keys to identify which particularindividual is attempting to retrieve his or her messages. For example,the caller may be asked to press “1” for John's messages or “2” forMary's messages. Such mail systems may require a subscriber to enter,e.g., 10-20 keys, prior to the subscriber being informed as to whetheror not there are any stored messages for the particular callingsubscriber.

In addition to requiring a caller to enter account information, mostvoice mail systems may require the subscriber to press additional keysand thereby generate DTMF tones, e.g., to replay or delete a message.

The large number of keys which must be depressed, and thus therelatively large amount of time and effort required merely to discoverwhether a message is waiting for a subscriber, is a major disadvantageof the known mail system described above.

In order to facilitate the routing of calls to an IP, e.g., forproviding voice mail and voice dialing services, a communicationprotocol referred to as the network facility access (“INFA”) protocol,was designed for communicating information between a subscriber and anIP via a central office switch. This protocol overcomes the need for asubscriber to dial a telephone number to be connected to an IP whencalling from the subscribers own telephone.

When the NFA protocol is enabled at the central office switch for asubscriber's telephone line, upon detecting an off-hook condition on thesubscriber's line the central office switch will immediately establish aconnection between the subscriber and an IP which is specified at thecentral office switch. In accordance with the NFA protocol, if thesubscriber begins dialing a telephone number while the connection to theIP is being established, the central office switch will terminate theprocess of connecting the subscriber to the IP and route the call in theusual manner.

While use of the NFA protocol makes it easier for a subscriber to gainaccess to an IP by eliminating the need to dial a telephone number to beconnected to the IP, there remains room for improvement in the manner inwhich subscribers are coupled to IPs and the manner in which IPsinteract.

For the most part, subscribers to voice mail services usually want to beconnected to a voice mail service when there is a new message waitingfor them and not at other times. Accordingly, automatically coupling asubscriber to an IP which provides voice mail services in response toevery off-hook condition of a subscriber can result in an inefficientuse of switch and IP resources. This is because, in many if not mostcases, the subscriber will be initiating the off-hook condition to placea call as opposed to connect to the voice messaging IP.

Problems may also arise with current methods of automatically connectinga telephone customer to an IP in response to an office hook conditionwhen the telephone customer subscribes to multiple services implementedon different IPs. In the known systems, a subscriber is generallycapable of being coupled automatically to a single IP in response to anoff-hook condition.

Accordingly, if a telephone customer subscribes to multiple telephonemessaging services, e.g., one for work and one for personal use, usingknown techniques he may only be able to be automatically connected toone of the services upon detection of an off-hook condition. This mayforce, for example, a person trying to retrieve business voice mailmessages to dial a telephone number corresponding to a work voice mailservice when at home and the home voice mail service when at work tocheck for messages.

Additional complications may arise in the known systems when, forexample, when a subscriber to a voice messaging service also subscribesto a voice dialing service implemented on a different IP than the voicemessaging service. In such a case, connecting a caller automatically tothe voice dialing service IP in response to an off-hook condition may bepreferable to connecting the caller to the voice messaging IP since thesubscriber will, in many cases, place calls more frequently than checkfor messages. Unfortunately, automatically connecting the subscriber toone IP will normally preclude automatic connection to the other IPthereby preventing a subscriber from automatically having access toservices provided on multiple IPs.

From the above discussion it is apparent that there is a need forimproved methods and apparatus for connecting subscribers to peripheraldevices. In particular, there is a need for methods and apparatus whichenable a subscriber to be automatically coupled to a plurality of IPs inresponse to an off-hook condition.

In addition, there is a need for methods of improving the use of switchand IP resources by selectively connecting subscribers to IPs when thesubscriber is most likely to use or desire access to the serviceprovided by the IP and not in response to every off-hook conditioninitiated by the subscriber.

In addition to improving the efficiency and ease of the subscriber to IPconnection process, it is desirable that the interaction with IP's besimplified from a subscriber's perspective. For example, it is desirablethat the number of telephone keys a subscriber must press to obtain adesired service be minimized.

It is also desirable, from a cost and implementation efficiencystandpoint, that circuitry found in one IP not be duplicated in otherIPs which will service the same subscribers. It is also desirable from acost and implementation standpoint that IP resources be used in anefficient and cost effective manner thereby minimizing overall IP andtelephone system hardware costs.

In view of the above, it is apparent that there remains room forconsiderable improvement in how IPs are connected to subscribers, theway in which they are interconnected, and the actual manner in which IPsare implemented.

SUMMARY OF THE PRESENT INVENTION

The present invention is directed to methods and apparatus forincreasing the utility and interoperability of peripheral devices, e.g.,voice mail devices and speech recognition platforms, used incommunications systems such as telephone systems.

In accordance with one embodiment of the present invention, a control IPis used to control the interaction of various IPs in the system and tocontrol user access to the various IPs.

As discussed above, it is desirable that a subscriber be able to obtainmessages from the subscriber's voice mail services regardless of whichIP the messages reside upon without requiring the subscriber to dial atelephone number corresponding to the voice mail IP. However, at thesame time, it is desirable from a telephone system efficiency standpointthat the subscriber not be automatically connected to a voice mail IP inresponse to every off-hook condition but rather when new messages arewaiting for the subscriber.

In accordance with one embodiment of the present invention, the centraloffice switch to which a subscriber is connected is dynamicallycontrolled, in response to IP status information, to automaticallyconnect a subscriber in response to an off-hook condition. In such anembodiment, the C.O. switch is controlled to connect the subscriber toan I.P. when the subscriber is likely to desire the services provided bythe IP but not at other times. In one particular embodiment, this isachieved by having an IP, e.g., a control IP, signal the C.O. switch toenable/disable use of the NFA protocol on a subscriber's line inresponse to IP status information. The IP status information mayinclude, e.g., message waiting information provided from a voice mail IPto a control IP though use of an SMDI line or a digital data/controlline.

The present invention, uses a control ID, in order to enable asubscriber to voice mail services implemented on multiple IPs automaticaccess, in response to an off-hook condition to the IPs when messagesare waiting. Upon detecting an off-hook condition, when the NFA protocolis enabled, the C.O. switch will automatically connect a subscriber tothe control IP. Through the use of a switching matrix, the subscriber isthen connected, e.g., sequentially, to one or more IPs which provide,e.g., voice mail services to the subscriber.

In one embodiment, in order to reduce the amount of input required by asubscriber, the control IP, as part of establishing a connection betweenthe subscriber and voice mail IP, automatically provides storedsubscriber account number and pin number information to the voice mailIP. Accordingly, the subscriber is provided, from the subscriber'sphone, access to his/her messages without having to enter anyinformation.

In order to further simplify interaction with service IPs, e.g., voicemail IPs, the control IP of the present invention includes speechrecognition functionality. In one embodiment, the connection between thesubscriber and the service IP is monitored by the control IP. Numbersand/or commands spoken by the subscriber are recognized and convertedinto DTMF tones which are commonly used for controlling service, e.g.,voice mail, IPs. In this manner, interaction with voice mail IPs issimplified from the subscriber's perspective since the subscriber canorally select certain options by, e.g., saying “one” as opposed tohaving to press a number on a telephone keypad.

Using the control IP to perform speech recognition for multiple serviceIPs has the advantage of allowing the same speech recognition hardwareto service multiple IPs. Thus, in accordance with the present inventionthe need to implement speech recognition hardware for which speechinteractions is to be supported, in each individual IP is eliminated.

In one particular embodiment, the functionality of a voice dialing IPand a control IP are merged. In such an embodiment, the control IPperforms the above discussed control operations as well as providesvoice dialing functionality. The control functionality of a control IPmay also be merged with that of a voice mail system if desired.

In order to provide speech recognition capabilities in a cost effectivemanner, in one embodiment of the present invention, the speechrecognition circuits which are used during different portions of a callare varied. In this manner, the least powerful and thus least costlyavailable speech recognition circuit capable of performing the necessaryspeech recognition operation at any given time is used. In oneparticular embodiment, this involves switching, upon connection to avoice mail IP, from a speech recognition circuit capable of performingspeaker independent and speaker dependent speech recognition, to onethat can perform only speaker independent speech recognition, e.g., ofnumbers and a few keywords or phrases.

In another embodiment, the amount of processing time allocated forperforming speech recognition for an individual subscriber isdynamically varied as a function of the stage of the call. In one suchembodiment, more processing time is allocated for speech recognitionwhen voice dialing is being performed than when instructions, in theform of numbers, are being provided to a voice mail IP. Such anembodiment is particularly well suited where a single processor is usedon a time shared basis to provide speech recognition functionality tomultiple connected subscribers at the same time.

In still yet another embodiment, a plurality of speech recognitioncircuits are employed with differing speech recognition capabilities andtherefore different individual implementation costs. In one suchembodiment, the system includes a high end speech recognition circuit,e.g., a large vocabulary speaker independent speech recognition circuit,a medium cost speech recognition circuit, e.g., a combined speakerindependent and speaker dependent speech recognition circuit capable ofidentifying a vocabulary of, e.g., 50 words, and a low end, e.g., smallvocabulary, speaker independent speech recognition circuit capable ofidentifying, e.g., 20 spoken numbers, phrases or words. A single speechcapture and segmentation circuit is used with the various speechrecognition circuits avoiding the need to duplicate such circuitry foreach speech recognition circuit. In one such embodiment, a service codereceived from the C.O. switch is used to determine the most appropriate,in terms of cost efficiency, of the various available speech recognizersto use.

In another embodiment, the captured speech is monitored by a defaultspeech recognition circuit, e.g., the combined speaker independent andspeaker dependent speech recognition circuit. During a call, the one ofthe plurality of speech recognition circuits, performing the speechrecognition task, monitors for keywords or phrases used as a trigger inselecting which one of the speech recognition units should be used atany given time. For example, in one such embodiment detection of thephrase “corporate directory” by the combined speaker independent andspeaker dependent speech recognition circuit will result in the largevocabulary speaker independent speech recognition circuit beingsubstituted for the combined speech recognition circuit. By dynamicallyswitching between speech recognition circuits in response to such voicetriggers, switching between speech recognition circuits can occuron-the-fly with multiple switches between speech recognition circuitsoccurring during a single phone call in a manner that is transparent tothe caller.

Using such a speech recognition system according to the presentinvention to service a large number of telephone subscribers in parallelallows the number of relatively powerful and therefore costly high endspeech recognition circuits to be minimized when servicing a givennumber of subscribers. Such a desirable result is achieved while stillproviding callers a high quality speech recognition service since therecognition circuit's capabilities are matched to each particularcaller's detected speech recognition needs at any given time.

By providing a speech recognition capability in accordance with thepresent invention, numerous callers can be provided speech recognitionservice in parallel at a lower cost than if all of the customers wereserviced by high end speech recognizers at all times.

In addition to the above described features, many other features andembodiments of the present invention are described in detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a known telephone system including IPs forproviding telephone users with voice mail service.

FIG. 2 is a block diagram of a telephone system implemented inaccordance with one embodiment of the present invention.

FIG. 3A is a block diagram of an intelligent peripheral implemented inaccordance with one embodiment of the present invention.

FIG. 3B is a database suitable for use as the database of the control IPillustrated in FIG. 3A.

FIG. 4 is a block diagram of a speech recognizer array implemented inaccordance with one embodiment of the present invention.

FIGS. 5A-5C are flow charts illustrating a method of operating thecontrol IP of FIG. 2 in accordance with one embodiment of the presentinvention.

FIG. 6 illustrates a telephone system implemented in accordance withanother embodiment of the present invention.

DETAILED DESCRIPTION

As discussed above, the present invention relates to methods andapparatus for increasing the utility and interoperability of peripheraldevices, e.g., voice mail devices and speech recognition platforms, usedin communications systems, e.g., telephone systems.

FIG. 2 illustrates a telephone system 200 implemented in accordance withone exemplary embodiment of the present invention. As illustrated thetelephone system 200 includes a plurality of telephone networks 210, 211which are coupled together by a fiber optic connection 32. The firsttelephone network 210 is illustrated in detail in FIG. 2. The secondtelephone network 211 may be the same as the first telephone network 210or, e.g., a known telephone network, e.g., the network 10 of FIG. 1.While two telephone networks are shown in the FIG. 2 embodiment, it isto be understood that the system may comprise any number of networks210, 211 and/or other additional communications networks which provide,e.g., Internet services.

As illustrated in FIG. 2, the telephone network 210 includes a pluralityof telephones 212, 214, a C.O. switch 216, a first voice mail IP 228, asecond voice mail IP 230, a control IP 232 and a switching matrix 234.The telephones 212, 214 are coupled to the central office switch 216 viaa first interface 218. Each telephone 212, 214 corresponds to atelephone subscriber who, in addition to subscribing to basic telephoneservice may also subscribe to one or more additional services such asvoice mail and/or voice dialing services provided though the use of IPs228, 230, 232.

The switch's interface 218 is coupled by a local bus to a CPU 220,memory 222, digit receiver 226 and a second interface 224. The CPU 220controls call routing and other switch operations in response to inputsreceived via the first and second interfaces 218, 224 in accordance withprogram routines stored in the memory 222.

The digit receiver 226, when active, detects the receipt of DTMF tonesand converts them to digits which are supplied to the CPU 220 for, e.g.,call routing purposes. The switch 216 is capable of implementing theknown NFA protocol for communicating between one or more of thetelephones 212, 214 coupled thereto and one or more of the IPs 228, 230,232. In one embodiment, the switch 216 is a Class V digitalcommunications switch.

The switch 216 is coupled to each one of the first and second voice mailIPs 228, 230 via its second interface 224, and one or more T1 links andSMDI lines. A voice and/or data connection can be established between asubscriber operating one of the telephones 212, 214 and either the firstor second voice mail IPs 228, 230 using one of the T1 links. The SMDIlinks between the voice mail IPs 228, 230 and the C.O. switch 216 areused to notify the central office switch when a new message has beenreceived and is waiting for a particular subscriber corresponding to oneof the telephones 212, 214 coupled to the central office switch. Thecentral office switch uses the SMDI information to activate a messagewaiting light on the particular subscriber's telephone 212, 214, whensuch message waiting functionality is supported by the telephone 212,214.

In accordance with the present invention, the SMDI lines of the firstand second voice mail IPs 228, 230 are also coupled to SMDI inputs ofthe control IP 232. In this manner, the control IP 232 receivesinformation regarding messages which are waiting for a voice mailsubscriber at the voice mail IPs, 228, 230.

In addition to being coupled to the voice mail IPs 228, 230, the controlIP 232 is coupled to the C.O. switch 216 by a recent change channel(RCC) and a plurality of T1 links. The T1 links are routed through theswitching matrix 234. The switching matrix 234 is controlled by aswitching control signal (SCS) received from to the control IP 232.Though use of the SCS the control IP 232 can control the routing ofincoming and outgoing lines to establish a connection to anyone of aplurality of line termination points including the first and secondvoice mail IPs 228, 230 and telephones 212, 214.

Where communication protocol conversion is required, the switchingmatrix 234 may be replaced by a programmable switch such as those madeby the Summa Four Corporation.

FIG. 3A illustrates a control IP 300 suitable for use as the control IP232 of the system 200. As will be discussed in detail below, inaccordance with the present invention, the control IP 300 may be used tosupport voice dialing services in addition to switch and call routingcontrol functions.

As illustrated, the control IP 300 comprises a plurality of speechrecognizer arrays, 302, 304, 306, a control interface 308, and anapplication processor 312. Each of the speech recognizer circuits 302 iscoupled to at least one T1 link for receiving and transmitting voice anddata to and from the switch 216. Each of the speech recognizer arrays302, 304, 306 is also coupled to an interface 318 of the applicationprocessor 312.

The application processor 312, includes the interface 318, a CPU 314,and a plurality of data storage devices including a memory 316, adatabase 310, and service logic 311. The memory 316 stores instructionsin the form of a program as well as data about the speech recognizerarrays 302, 304, 306 and the speech recognition capabilities of variouscircuits included therein. The service logic includes data and programcode used to implement one or more services, e.g., a voice dialingservice. The program stored in the memory 316, in conjunction with theinformation and program code stored in the service logic 311, whenexecuted by the CPU 314, controls the operation of the control IP inaccordance with the present invention. The interface 318 is used tocouple and interface the various components of the applicationprocessor, such as the database 310, CPU 314, memory 316 and servicelogic 311 to the speech recognizer arrays 302, 304, 306 and the controlinterface 308. The interface 318 converts the various signals receivedby the application processor 312 into a format that can be interpretedand processed by the CPU 314 as well as converts signals generated bythe CPU 314 into a signal format that can be used to control andinteract with the various circuits coupled to the application processor312.

The control interface 308 is responsible for receiving SMDI signalinputs from the voice mail IPs 228, 230 which form part of the network210. The information regarding waiting messages, e.g., subscriber'saccount number and message waiting indicator, received via the SMDIlinks, is conveyed to the application processor 312. The applicationprocessor 312 is responsive to the information received via the SMDIlinks which it uses in conjunction with information from the database310 to determine the action which is to be taken by the control ±P 300.Via the control interface 308, the application processor can instruct,e.g., using the recent change channel (RCC), the C.O. switch 216, toenable/disable the NFA protocol on a particular subscriber's line and/orperform other operations such as enable/disable the C.O. switch's digitreceiver 226 with regard to an ongoing connection. In addition, via thecontrol interface 308, which generates the switching matrix controlsignal (SCS), the application processor 312 can control the switchingmatrix 234 to establish connections via the C.O. switch with one or moreIPs and/or destination telephones.

The database 310, which is included in the application processor 312, isused to store relevant subscriber information. FIG. 3B illustrates anexemplary control IP database 310.

As illustrated, the database 310 comprises a plurality of entries. Oneset of entries, represented by a horizontal row, is associated with eachsubscriber being serviced by the control IP 232. Each set of entriesincludes information pertinent to servicing one subscription which, inmost cases, will correspond to a single individual subscriber. However,in the case of a multi-party mailbox, the single subscription maycorrespond to multiple individuals.

In the FIG. 3B embodiment, columns 1-9 represent different informationentries which are maintained in the database 310 for each subscription.Column 1, corresponds to subscriber name information, column 2corresponds to a subscriber ID number. The subscriber ID number may be,e.g., a number used to identify the subscriber for voice mail purposes.Column 3 corresponds to subscriber telephone number information. Thetelephone number information may be used, e.g., to identify to the C.O.switch 216, the line on which the NFA protocol is to beenabled/disabled. In addition, in the case where the SMDI link providesmessage waiting information associated with a subscriber's telephonenumber, the control IP 232 can identify the particular subscriber forwhich a message is waiting by using the received telephone number andthe telephone number information stored in the database 310.

Column 4 of the database 310 corresponds to the subscriber's personalidentification number (PIN) which the subscriber would normally use toaccess the messaging service or services to which the subscribersubscribes.

While, in columns 2 and 4 only one subscriber and PIN is shown for eachsubscriber, it is to be understood that a different subscriber ID andPIN may be stored for each one of a plurality of messaging services towhich a customer subscribers.

Columns 5, 6, 7, and 8 include status and service information used bythe IP 232 in determining how to control call routing, e.g., which IPs acustomer should be connected to, and what services are to be provided toa customer.

Column 5, corresponds to NFA protocol status. If the NFA protocol isenabled for a particular subscriber, the subscriber will automaticallybe coupled to the control IP 232 when the C.O. switch detects anoff-hook condition on the subscriber's line.

If the NFA protocol is not enabled for a particular subscriber, thatsubscriber will not be automatically connected to the control IP when anoff-hook condition is initiated. Under such circumstances, thesubscriber would have to dial the number of an IP to gain access to hisor her voice mail service or other IP provided service.

Database column 6 corresponds to message waiting status. If a message iswaiting for a particular subscriber, e.g., as indicated by the receiptof an SMDI signal including the subscriber's telephone number, thiscolumn will include an IP identifier identifying the IP where a messageis waiting. In the event that messages are waiting on multiple IPs for asubscriber, the entry in column 6 associated with the subscriber willinclude an IP identifier for each IP with a waiting message.

Database column 7 indicates the type of message prompt to be played tothe subscriber once a connection is established between the subscriberand the control IP. In the case where no message is waiting, a messagethat there are no waiting messages is played to the subscriber in theevent that the subscriber connects to the control IP, e.g. by dialingthe IP. Accordingly, in column 7, “NONE” is indicated with regard to theprompt that should be used for subscribers without waiting messages. Inthe case where a voice message is waiting for an individual subscriberto an individual voice mail service, default message is played to thesubscriber upon connection to the IP. The default message may besomething like “You have at least one new message.” In at least oneembodiment the default message provides a user with the actual number ofnew waiting messages. In the case where the voice mail service beingprovided corresponds to a multi-party account, as in the case of thelast account listed in database 310, a prompt identifying the individualfor whom the waiting message is intended may be played when suchinformation is available. For example, in one embodiment the promptwhich is played states: “NEW MESSAGE FOR: NAME” where NAME is the nameof the individual to whom the waiting message is directed. Whenindividual name information is not available regarding the intendedrecipient of a waiting message the default message prompt may be used.

Column 8 indicates whether the customer subscribes to a Voice Dialingservice supported by the control IP 232. As will be discussed below,this information is important with regard to call flow handling by thecontrol IP 232. Normally, for voice dialing service subscribers, the NFAprotocol feature will be enabled at the central office switch 216 evenwhen messages are not waiting for the subscriber. This allows thesubscriber to obtain direct access to the voice dialing capability ofthe control IP without having to dial the IP.

As discussed above, in the case where a customer subscribes to a voicemail service but not a voice dialing service, the NFA protocol featureis disabled in accordance with the present invention at the C.O. switchwhen there are no messages waiting for the subscriber.

Column 9 includes voice template and voice recording information (TR)used for supporting voice dialing services for subscribers to the voicedialing service. For each voice dialing service subscriber, at least onespeaker dependent speech recognition template is stored for each name tobe recognized using speaker dependent speech recognition techniques. Arecording of the name corresponding to a speech template, e.g., madewhen the template was created, is also stored in the database 310 sothat it can be played back to the subscriber as a way of indicating tothe caller which name was identified by the speech recognition circuit.A telephone number, to be dialed, is also normally stored in thedatabase 310 for each name for which there is a stored template.

With regard to customer John Smith, columns 5-9 of the first row ofdatabase 310 indicate, for example, that the NFA protocol is not enabledfor his telephone line, that there are no messages waiting for him, thata prompt is to be played to John Smith indicating that there are nowaiting messages in the event that he establishes a connection with thecontrol IP, e.g., via a direct dial operation, that he does notsubscribe to the control IP's voice dialing service, and that there areno stored templates or recordings for John Smith.

With regard to customer Mary Wells, columns 5-9 of the second row ofdatabase 310 indicate, for example, that the NFA protocol is enabled forher telephone line, that there is one or more messages waiting for heron the first voice mail IP 228, that a default prompt is to be played toher indicating that there are one or more waiting messages in the eventthat she establishes a connection with the control IP, e.g., viainitiating an off-hook condition on the telephone line identified by thetelephone number listed in database 310, that she does not subscribe tothe control IP's voice dialing service, and that there are no storedtemplates or recordings for her.

FIG. 4 illustrates a speech recognizer array 400 suitable for use as anyone of the speech recognizer arrays 302, 304, 306. The speech recognizerarray 400 includes a T1 interface for coupling the recognizer array to aT1 link, first and second speaker independent speech recognitioncircuits 404, 406, a primary speech recognizer 407 and a DTMF tonegenerator/receiver 410. These circuits 402, 404, 406, 407, 410 arecoupled together by a data bus 403 and a high bandwidth bus 401 capableof carrying voice communications. The high bandwidth bus 401 is alsocoupled to the control IP's application processor 312.

The data bus 403 couples a CPU 412, memory 414 and an Ethernet adapter416 to the data bus 403 thereby allowing them to interact with thevarious speech recognition circuits 404, 406, 408, T1 interface 402 andDTMF tone generator/receiver 410. The Ethernet adapter 416 is used tocouple the data bus 403 to the application processor 312.

The primary speech recognizer 407 includes a speech capture circuit 409and a combined speaker independent and speaker dependent speechrecognition circuit 408. The speech capture circuit 409 is used tocollect speech data and to arrange it into segments which are thensupplied to one of the speech recognition circuits 404, 406 or 408 forprocessing. By coupling the various speech recognition circuits 404,406, 408 and the speech capture circuit 409 to the same high speed bus401, the speech capture circuit 409 can transmit captured speech to anyof the voice recognition circuits 404, 406, 408 thereby eliminating theneed to provide a separate speech capture circuit 409 for each of thespeech recognition circuits 404, 406, 408.

Each of the speech recognition units 404, 406, 408 include a processorand memory which are used to perform speech recognition operations. Thelarge vocabulary speaker independent speech recognition circuit 404 maysupport, e.g., the recognition of, e.g., over 100 words or phrases usingspeaker independent speech recognition techniques. The combined speakerindependent and speaker dependent speech recognition circuit maysupport, e.g., the recognition of 20-75 words or phrases. In contrast,the small vocabulary speaker independent speech recognition circuit maysupport the recognition of 20 or fewer words, e.g., spoken numbers orkeywords, which may be included in phrases.

Because of the relative complexity of the speech recognition tasks to beperformed, the large vocabulary recognition circuit 406 will normally beimplemented using a relatively powerful CPU and a large amount ofmemory. The combined speaker independent and speaker dependent speechrecognition circuit 408 will normally be implemented using a lesspowerful CPU and less memory than the speech recognizer 406 while thesmall vocabulary speaker independent speech recognition circuit 404 willnormally be implemented using the least amount of memory and the leastpowerful CPU out of the three speech recognition circuits 404, 406, 408.The recognition circuit 404, uses the least powerful CPU and leastmemory because it needs to perform the least processing operations perunit time, out of the three recognizer circuits, for each caller beingserviced to perform real time speech recognition. In contrast, the largevocabulary recognition circuit 406 has to perform the most processingoperations, out of the three circuits 404, 406, 408, per caller per unittime, to perform real time speech recognition and therefore includes themost powerful CPU out of the speech recognition circuits 404, 406, 408.

The large vocabulary speaker independent speech recognition circuit 406is capable is capable of detecting a large number of names and phrasesusing speaker independent speech recognition techniques. For thisreason, it is particularly well suited for, e.g., providing corporatedirectory information where it is desirable to be able to identifyhundreds or even thousands of names of individual people and words whichare, e.g., part of the name of a corporate department title. The largevocabulary speech recognition circuit 406 may be thought of as a highend, e.g., relatively expensive and powerful, speech recognitioncircuit.

The small vocabulary speaker independent speech recognition circuit 404supports the recognition of relatively few words or phrases, e.g., lessthan 20. In one embodiment the circuit 404 is used to recognize numbersspoken as part of a phrase such as “press number”. In addition, invarious embodiments, it is used to recognize words which may beinterpreted as a trigger to switch to the use of another voice dialingcircuit.

The combined speaker independent and speaker dependent speechrecognition circuit 408 may be characterized as a mid-level speechrecognition circuit capable of recognizing, e.g., up to 100 words orphrases in one exemplary embodiment. The circuit 408 is particularlywell suited for voice dialing purposes and may be the same as or similarto the speech recognition circuit described at length in U.S. Pat. No.5,719,921 which is hereby expressly incorporated by reference.

The combined speaker independent and speaker dependent speechrecognition circuit 408 is used, in one embodiment, to support voicedialing. Voice dialing generally involves performing speaker independentspeech recognition used to identify commands, e.g., dial, forward,cancel call forward, and speaker dependent speech recognition toidentify names, e.g., the names of the people to be called. See, U.S.Pat. No. 5,719,921 for a discussion of the use of speaker independentand speaker dependent speech recognition to support voice dialingservices. In order to support speaker dependent voice dialing servicesspeaker dependent speech recognition templates, e.g., of names arestored in the database 310 for each voice dialing service subscriber.This information is retrieved, stored in the memory of the speechrecognition circuit 408, and used to support voice dialing, when aconnection is established between the control IP 232 and a voice dialingservice subscriber.

In accordance with one embodiment of the present invention, the speechrecognition circuit 404, 406, 408 which is used to support speechrecognition is dynamically changed according to the speech recognitiontask to be performed during the particular stage of a call. In thismanner, hardware is used in a more cost effective manner than would bepossible if an unnecessarily powerful, and therefore, relativelyexpensive, speech recognition circuit were used for all stages of callprocessing.

As will be discussed further below, in accordance with one embodiment ofthe present invention, the combined speaker independent and speakerdependent speech recognition circuit 408 is used during portions of acall where voice dialing is to be provided. However, during portions ofa call where the detection of, e.g., spoken digits alone or as part of aphrase, is the primary concern, the small vocabulary speaker independentspeech recognition circuit 404 is used. In cases where large vocabularyspeaker independent speech recognition operations are required, e.g.,providing corporate directory information, circuit 406 is used.

In accordance with the present invention, the dynamic switching betweenspeech recognition units 404, 406, 408, as a call progresses and/or theservice being provided the subscriber changes during a call, isperformed under control of the application processor 312 and/or CPU 412.

In one particular embodiment, when a call connection is initiallyestablished with the control IP 232 a service code, e.g., a numberindicating voice dialing, corporate directory, or a voice mail servicerequest, is provided by the switch 216 to the control IP. Subsequently,a new service code may be supplied to the control IP during the samecall connection, e.g., in response to the switch detecting the pressingof the * key followed by a number indicating a requested service such asvoice mail service.

In one such embodiment, CPU 412 of the speech recognizer array detectsthe service code associated with a particular call connection andassigns one of the speech recognizer circuits 408, 406, 404 to servicethe call as a function of the service code. In the event that anotherservice code is received during the same call connection, the CPU willre-assess the speech recognition circuit assignment in response toreceipt of the new service code. Thus, as a result of receipt of a newservice code, the speech recognizer assigned to service a call may bedynamically changed during the call. For example, if a voice dialingservice code is initially received, the combined speaker independent andspeaker dependent speech recognition circuit 408 would be assigned toservice the call. If during the call a voice message service code werereceived, the CPU 412 would de-assign the combined speech recognizer andassign the small vocabulary speaker independent speech recognition toservicing the call.

In another embodiment, the call connection established with the controlIP 232 is monitored throughout the period in which the call connectionis maintained for spoken words or phrases, referred to herein as“trigger phrases” which may be used to determine the service to beperformed and thus which speech recognizer is best suited for servicinga particular portion of a call. For example, detection of the phrase“corporate directory” would be interpreted as indicative of a corporatedirectory information request and, in response to detection of such aphrase, the large vocabulary recognition circuit 406 would be assignedto service the call. Detection of the word “DIAL” or a spoken nameincluded in the caller's voice dialing database could be interpreted asindicating a voice dialing service request. In such an instance thecombined speech recognition circuit 408 would be assigned to service thecall. Similarly, the phrase “voice mail” would trigger use of the smallvocabulary speech recognition circuit 404 to service the call.

Each of the speech recognition circuits 404, 406, 408 can use speakerindependent speech recognition techniques to detect such keywords ortrigger phrases. Accordingly, such keywords or trigger phrases can bedetected at any point during a call causing the CPU 412 to reassess andpossibly re-assign the call to a different one of the speech recognitioncircuits 404, 406, 408. In this manner the CPU 412 matches the requestedservice to the most cost effective one of the speech recognitioncircuits available.

Operation of the telephone system 200 of the present invention, and useof the control IP 232 will now be discussed in detail with reference toFIGS. 5A-5C which are a flow diagram illustrating the operationsperformed by the control IP in servicing a subscriber.

Operation of the control IP begins in step 502, the START step. In thisstep the control IP's application processor 312 is initialized, the IPcontrol program stored in the memory 316 is loaded and executed by theCPU 314. Once various initialization procedures have been completedcontrol IP operation proceeds to step 504. In step 504, the applicationprocessor 312, via the speech recognizer arrays 303, 304, 306 andcontrol interface 308, monitors for inputs to the control IP, (e.g.)from either the SMDI lines or T1 links coupled to the control IP 232.

In step 506, a determination is made by the application processor as towhether or not an input has been detected. If no input has been detectedoperation proceeds once again to the monitoring step 504. If, however,in step 506, a message waiting indicator signal is detected, e.g., onone of the SMDI lines, operation progresses to step 508.

In step 508 the subscriber for which the message is intended isidentified. This is accomplished by, e.g., using either a telephonenumber or subscriber ID received from the SMDI line in conjunction witha message waiting signal, with the corresponding subscriber informationstored in the database 310. Once the subscriber for which the message isintended is identified, and the corresponding data base entries for thesubscriber retrieved from the database 310, operation proceeds to step510.

In step 510, a determination is made, e.g., from the data included incolumn 5 of the database 310, as to whether or not the NFA protocol isactive at the C.O. switch for the identified subscriber for which themessage is intended.

Active NFA protocol status at the switch for the identified subscriberwill result in the identified subscriber being coupled automatically tothe control IP 232 in response to the detection of an off-hook conditionon the identified subscriber's line.

Normally, if there is already one or more waiting messages for theidentified subscriber, not including the current message being reportedby the detected signal on the SMDI line, the NFA protocol will be activefor the identified subscriber as the result of the earlier unretrievedwaiting messages. Similarly, if the subscriber subscribes to the voicedialing service supported by the control IP 232, the NFA protocol willbe enabled for the subscriber.

If, in step 510 it is determined that the NFA protocol is already activefor the identified subscriber, operation proceeds directly to step 514.

However, if in step 510 it is determined that the NFA protocol is notactive for the subscriber at the C.O. switch operator proceeds to step512 wherein a control signal is sent by the control IP to the C.O.switch, via the recent change channel (RCC). The control signalinstructs the C.O. switch to connect the identified subscriber to thecontrol I.P., in response to an off-hook condition on the identifiedsubscriber's telephone line, e.g., by using the NFA protocol. From step512, operation progresses to step 514.

Step 514 involves updating of the database 310 to reflect changes in thestatus information associated with the identified subscriber. Thisinvolves, e.g., changing the NFA status information if it was activatedin step 512, and updating the message waiting and message promptinformation to reflect the waiting message. For example, the messagewaiting status information in col. 6 may be updated to reflect thatthere is an additional waiting message for the identified subscriber andthe VMIP where the message is waiting. In addition, the message promptinformation, included in database column 7, will be modified, ifnecessary, so that the identified subscriber will be informed of thewaiting message upon connecting to the control IP.

Once the subscriber database is updated in step 514, operation returnsto the monitoring step 504 wherein the control IP monitors foradditional inputs. From step 504, operation proceeds to step 506.

If, in step 506, a subscriber connection signal is detected as a resultof the monitoring for received signals which occurred in step 504,operation proceeds to step 520 via flow chart connectors 516, 518. Thesubscriber connection signal will normally include informationsufficient to identify the subscriber for database access purposes,e.g., the subscriber's telephone number or account number information.For purposes of this exemplary discussion, the exemplary individualsubscriber who established the connection to the IP will be referred toas “the connected subscriber”.

In step 520, the database 310 is accessed and the information includedtherein, pertinent to the connected subscriber, is retrieved. Theretrieved information may include, e.g., in the case where the caller isa voice dialing service subscriber, speaker dependent voice dialingtemplates and recordings in addition to the other informationillustrated in FIG. 3B.

Once the subscriber data is retrieved from the database 310, operationproceeds to step 522 wherein a determination is made, using theretrieved information, as to whether the connected subscriber is a voicedialing subscriber. If the answer to this inquiry is yes, operationproceeds to step 524 wherein the voice dialing service is provided tothe caller. This step involves, e.g., loading retrieved speakerdependent speech recognition templates and recordings into the speechrecognition circuit 408. It also involves controlling the recognitioncircuit 408 so that it monitors the line which connects the subscriberto the control IP and performs speech recognition operations on speechtransmitted thereon.

Once the voice dialing service is activated, if the speech recognitioncircuit 408 receives an instruction to dial a telephone number over theline connecting the subscriber to the control IP 232, a voice dialingoperation will be performed by the IP in a manner that is the same as orsimilar to the manner in which known voice dialing service is provided.

From step 524 operation proceeds to step 526. Operation will proceeddirectly from step 522 to step 526 if in step 522 it is determined thatthe connected subscriber is not a voice dialing subscriber.

In step 526, a determination is made from the retrieved databaseinformation, e.g., by the application processor 312, as to whether thereare any new messages waiting for the connected subscriber. If there areno new messages, operation proceeds to step 527. In step 527, the calleris notified, e.g., via an audio prompt that there are no new messages.The connection between the IP and the subscriber is then allowed toterminate, in step 528, in accordance with voice dialing procedures inthe event a voice dialing call is placed or if the subscriber hangs up.

In one embodiment, in the case where the connected subscriber is a voicedialing customer, a preselected amount of time may be allowed to pass instep 527 before the no new messages prompt is played. If the subscriberinitiates a voice dialing call during this period, the call will beallowed to terminate as a conventional voice dialing call without theprompt being played to the subscriber.

If, in step 526 it is determined that there are new messages for thesubscriber, operation proceeds to step 530. In step 530, the subscriberis notified of the presence of a waiting message, e.g., by playing theprompt indicated in the database 310 for the connected subscriber. Fromstep 530 operation proceeds to step 531 wherein an inquiry is made as towhether or not the subscriber wants to retrieve the messages. Theinquiry may involve playing of a message asking if the subscriber wantsto retrieve the messages followed by monitoring of the call connectionto detect a spoken YES or NO response.

If, in step 531, a NO response is detected operation proceeds to step528 wherein the call connection is allowed to terminate according tonormal voice dialing procedure or NFA protocol operation.

If, in step 531, a YES response is detected indicating that thesubscriber wants to retrieve the waiting messages operation proceeds tostep 532.

In step 532 the control IP establishes a connection between thesubscriber and a voice mail IP where one or more messages are waitingfor the subscriber. The voice mail IP 228, 230 to which the subscriberis connected is determined by the information in the database 310 whichindicates which IP contains the subscriber's waiting message ormessages.

As part of the process of establishing the connection between theconnected subscriber and voice mail IP, the control IP seizes a line ofone of the T1 links coupled to the control IP. In addition, it controlsthe switching matrix 234 to route the subscribers call, via the C.O.switch 216, to the desired voice mail IP 228, 230. In this manner, thecontrol IP 232 establishes a connection between the subscriber and thevoice mail IP 228 or 230 while remaining connected to the line.

As part of the process of establishing the connection between thesubscriber and voice mail IP 228 or 230, the control IP supplies boththe connected subscriber's account number and PIN number information tothe voice mail IP thereby eliminating the need for the connectedsubscriber to enter this information.

Once a connection is established with one of the voice mail IPs 228,230, the control IP 232 signals, in step 534, the C.O. switch 216 totake its digit receiver off-line. In step 536 voice dialing support isde-activated if it was enabled. Accordingly, by the end of step 536, therelatively expensive combined speaker independent and speaker dependentspeech recognition circuit 408 used for voice dialing is released fromservicing the connected subscriber. In addition, because the DTMFreceiver of the central office switch is disable with regard to theconnected subscriber, the connected subscriber is free to interact withthe voice messaging IP through the use of DTMF or voice instructionswithout accidentally initiating a telephone call.

From step 536 control IP operation proceeds to steps 542 and 548 viaconnectors 538, 540.

The path comprising steps 542, 544, 546 represents speech recognitionand DTMF generation functionality supported by the control IP 232 whichis provided to facilitate subscriber interaction with a voice mail orother connected service IP. This functionality is provided through theuse of one of the speaker independent speech recognition circuits 404,406 and the DTMF tone generator/receiver 410. While speaker independentrecognition is used in the illustrated embodiment speaker dependentrecognition may be used alone or in combination with speaker independentspeech recognition

Step 542 involves monitoring the line connected to the subscriber forspeech such as the instruction “press one” or “one” which is to berecognized and converted into DTMF tones. Upon one of the speechrecognition circuits 404 or 406 detecting a spoken digit, e.g., as partof a phrase such as “press one”, a signal is sent to the DTMF tonegenerator circuit 410 instructing it to generate a DTMF tonecorresponding to the detected digit. In step 544, one or more DTMF tonesare generated in response to the speech recognized in step 542.

The generated DTMF tones 546 are transmitted by the control IP 232 tothe voice mail IP 228 or 230 to which the subscriber is connected.However, to avoid annoying the subscriber with the DTMF tones, in oneembodiment, the line to the subscriber is muted while the tones aretransmitted to the voice mail IP. Thus, the voice mail IP receives theDTMF signals generated from the subscribers speech and can respondthereto without the subscriber having to enter the signals by pressingkeys and without the subscriber having to listen to the tones.

After transmission of the generated tone operation proceeds to step 542where the connection is monitored for additional speech. The process ofmonitoring the connection to a voice mail IP will continue for theduration of the connection to the voice mail IP. Accordingly, whileconnected to the voice mail IP 228 or 230, the subscriber will have theopportunity to input responses or commands to the voice mail IP usingspeech as opposed to having to press keys of a telephone.

The path beginning with step 548 may occur in parallel with the pathbeginning with step 542. In step 548 the connection between thesubscriber and the voice mail IP 228, 230 is monitored for a voice mailIP connection termination control signal e.g. from the voice mail IP orsubscriber. Operation progresses to step 550 when a termination signalis detected. In step 550 the connection between the subscriber and thevoice mail IP 228, 230 is terminated. From step 550 operation proceedsto step 552 wherein the database 310 is updated to reflect the review ofmessages by the subscriber which were stored on the voice mail IP towhich the subscriber was connected.

After termination of the connection with the voice mail IP 228 or 230, adetermination is made in step 554 as to whether or not there are newmessages waiting for the subscriber on another voice mail IP.

This is done by, e.g., checking the updated database entry for theconnected subscriber indicating the message waiting status. For example,if the connected subscriber were Bob Barker, after connecting to thesecond voice mail IP 230, there would still be voice mail messages onfirst voice mail IP 228. However, if the connected subscriber were MaryWells, there would be no additional messages waiting for the subscriber.

If in step 554, it is determined that there are additional new messageswaiting for the subscriber, e.g., on a different voice IP, operationproceeds to step 524 thereby causing the subscriber to automatically beconnected to the IP with the messages.

However, in step 554 if it is determined that there are no more messageswaiting for the connected subscriber, operation proceeds to step 558wherein a determination is made as to whether or not the connectedsubscriber is a voice dialing subscriber. If the connected subscriber isa voice dialing subscriber, operation proceeds to step 560 wherein thevoice dialing function of the control IP 232 is enabled by, e.g.,re-connecting the combined speaker independent and speaker dependentspeech recognition circuit 408 to the connected subscriber's line.

In addition, the C.O. switch's digit receiver 226 is also enabled instep 560. Accordingly, the connected subscriber can complete a call to aspoken or dialed telephone number without the need to hang-up afterreceiving his or her messages. Under such circumstances, termination ofthe connection with the caller will occur in accordance with normalvoice dialing procedures which may include the connected subscriberhanging up the telephone.

While not explicitly stated in the flow diagram of FIGS. 5A-5B it is tobe understood that a connected subscriber can terminate the call at anytime by hanging up. Hanging up causes the control IP 232 to terminatethe subscriber's connection with any voice mail IP's which may exist atthe time of call termination. In addition, the control IP 232 updatesthe database 232 to reflect the retrieval of messages prior to calltermination if, in fact, any messages where retrieved.

FIG. 6 illustrates a telephone system 600 implemented in accordance withanother embodiment of the present invention. The system 600 comprises aplurality of telephone networks 610, 211 coupled together by a fiberoptic line 32. The telephone network 610 comprises many of the sameelements as the network 210. Elements of the FIG. 2 and FIG. 6embodiments which are the same, or similar, bear the same referencenumbers and will not be described again.

The FIG. 2 and FIG. 6 embodiments differ principally in the way in whichthe telephone network's peripheral devices, including first and secondvoice mail IPs 628, 630 and a control IP 632 are connected together.Note that SMDI lines are not used in the FIG. 6 embodiment as they arein the FIG. 2 embodiment. Instead, digital lines 631, 633 are used toconnect the first and second voice mail IPs 631, 633 to the control IP632.

By using digital lines in this manner, information not available over anordinary SMDI line can be supplied to the control IP 632. For example, abrief message introduction may be sent by the voice mail IP to thecontrol IP 632. The introduction may include a 15 or 30 second soundmessage provided by a person leaving the message to identify him orherself. Alternatively, in the case of a multi-person account, theinformation provided by the digital line 631 or 632 may be a recordingidentifying the name of the recipient for which the message is intended.In addition to receiving information about waiting messages from thefirst and second voice mail IP's, in one embodiment, the control IP 632uses the lines 631, 633 when establishing a connection between aconnected caller and subscriber. The lines 631, 633 may be implementedusing a plurality of digital data and/or control lines. In oneparticular embodiment the lines 631, 632 are implemented as lines whichimplement the known signaling system 7 (SS7) protocol frequently used toimplement telecommunications and data networks.

While the use of a control IP to facilitate the interaction of multipleIPs which provide services to the same subscriber has been described inthe context of a voice mail embodiment, it is to be understood, that thefeatures of the present invention are applicable to facilitatingsubscriber/IP access and IP interaction regardless of the type or typesof services being provided by the IPs.

While the substitution of speech recognizer circuits has been discussedabove as a cost effective method of providing speech recognitionservices to a plurality of telephone users, in accordance with oneembodiment of the present invention, multiple speech recognizers areused to process the same speech. In one such embodiment, a low or midlevel speech recognizer circuit such as the recognizer circuit 404 or408 is used to service all or most of a call. For portions of a callwhere more complicated, e.g., large vocabulary, speech recognition isrequired, an additional speech recognizer such as the speech recognitioncircuit 406 is also assigned to service the call in conjunction with theother speech recognizer. By switching in a high end speech recognitionunit for the small portion of a call where, e.g., large vocabularyspeech recognition is required, speech recognition service is providedwithout having to use the large vocabulary speech recognizer for theentire duration of the call. In addition, speech recognitionfunctionality included in the low or mid level speech recognizer circuitneed not be duplicated in the higher end speech recognition circuitwhich is switched in to supplement the speech recognition capabilitybeing provided.

Additional embodiments and features of the present invention will bereadily apparent to those skilled in the art in view of the abovediscussion and exemplary embodiments set forth in the presentapplication.

What is claimed is:
 1. A method of performing speech recognition, themethod comprising the step of: monitoring for a signal indicative of atype of service to be provided to a user of a communication line;selecting a first one of a plurality of speaker independent speechrecognition circuits having differing speech recognition vocabularies asa function of the signal indicative of the type of service to beprovided; and connecting the first selected one of the plurality ofspeech recognition circuits to the communication line.
 2. The method ofclaim 1, wherein said signal indicative of the type of service to beprovided indicates a voice mail service is to be provided.
 3. The methodof claim 1, wherein said signal indicative of the type of service to beprovided indicates a voice dialing service is to be provided.
 4. Themethod of claim 1, further comprising the step of generating a DTMF tonein response to speech.
 5. A method of providing a speech recognitioncapability to peripheral devices included in a telephone system having acaller and a plurality of peripheral devices, the method comprising thesteps of: establishing a first connection through a telephone switch,the first connection being between a caller and a first peripheraldevice including a first speech recognition unit; establishing a secondconnection through said telephone switch, the second connection beingbetween the first peripheral device and a second peripheral device;operating a first speech recognition unit included in the firstperipheral device to perform a speech recognition operation on speechprovided by the caller; operating the first peripheral device togenerate a signal indicating at least some information recognized byperforming said speech recognition operation; and supplying thegenerated signal via the second connection to the second peripheraldevice.
 6. The method of claim 5, where the signal indicating at leastsome information is a DTMF signal.
 7. A method of providing a speechrecognition service during a telephone call in a telephone systemincluding a caller, a switch, a peripheral device and a plurality ofdistinct speech recognition circuits including a speaker independentspeech recognition circuit and a combined speaker independent andspeaker dependent speech recognition circuit, the method comprising thesteps of: monitoring the status of the telephone call to detect when thecaller is coupled to the peripheral device; utilizing the combinedspeaker independent and speaker dependent speech recognition circuit toperform a speech recognition operation during a first portion of a callwhen the caller is not coupled to said peripheral device; and utilizingthe speaker independent speech recognition circuit to perform a speakerindependent speech recognition operation during a second portion of thecall during the time period in which the caller is coupled to theperipheral device.
 8. The method of claim 7, further comprising the stepof: monitoring the output of the combined speaker independent andspeaker dependent speech recognition circuit to detect speech indicativeof a voice dialing operation.
 9. The method of claim 8, wherein the stepof monitoring the output of the combined speaker independent and speakerdependent speech recognition circuit includes the step of: monitoringfor the word DIAL.
 10. The method of claim 8, wherein the step ofmonitoring the output of the combined speaker independent and speakerdependent speech recognition circuit includes the step of: monitoringfor a name included in a voice dialing directory of the caller.
 11. Themethod of claim 8, wherein the step of: utilizing the speakerindependent speech recognition circuit to perform a speaker independentspeech recognition operation during a second portion of the callincludes the step of: monitoring for a phrase including a spoken number.12. The method of claim 8, wherein the step of: utilizing the speakerindependent speech recognition circuit to perform a speaker independentspeech recognition operation during a second portion of the callincludes the step of: monitoring for a spoken number.
 13. The method ofclaim 12, further comprising the step of: generating a DTMB tonecorresponding to each detected spoken number.
 14. The method of claim 7,further comprising the step of: supplying the results of a speechrecognition operation performed by the speaker independent speechrecognition circuit to said peripheral device.
 15. A telephone systemcomprising: a telephone; a first telephone switch peripheral device forproviding a service to a user of the telephone; a communications networkfor coupling the telephone to the first telephone switch peripheraldevice; a second telephone switch peripheral device coupled to thecommunication network, the second telephone switch peripheral deviceincluding: a speech recognition circuit for performing a speechrecognition operation on speech obtained for said caller; means forgenerating a signal indicating at least one word recognized in speechprocessed by said speech recognition circuit; and means for transmittingthe generated signal to the first telephone switch peripheral device.16. The telephone system of claim 15, wherein said means for generatinga signal in response to speech recognized by said speech recognitioncircuit includes a tone generator; and. wherein the communicationsnetwork includes a telephone switch.
 17. The telephone system of claim15, wherein said speech recognition circuit is a first speakerindependent speech recognition circuit; the second peripheral devicefurther including: a second speaker independent speech recognitioncircuit having different speech recognition capabilities than the firstspeaker independent speech recognition circuit.
 18. A telephone system,comprising: a telephone; a peripheral device for providing a service toa caller using the telephone; a switch coupled to the telephone forconnecting the telephone to the peripheral device; a combined speakerindependent and speaker dependent speech recognition circuit coupled tothe switch; a speaker independent speech recognition circuit coupled tothe switch; and a central processing unit coupled to the combined speechrecognition circuit and the speaker independent speech recognitioncircuit for monitoring the status of a call connection between theswitch and the peripheral device while the connection is beingestablished and during the period that the call connection is maintainedand dynamically switching between the use of the combined speechrecognition circuit and the speaker independent speech recognitioncircuit.
 19. The telephone system of claim 18, wherein the combinedspeaker independent and speaker dependent speech recognition circuit,speaker independent speech recognition circuit, and central processingunit are included in a second peripheral device coupled to the switch.20. The telephone system of claim 19, wherein the second peripheraldevice further includes: a DTMF tone generator; and means for performinga voice dialing operation.
 21. The telephone system of claim 20, whereinthe first peripheral device is a voice mail peripheral device used forstoring and supplying messages to the caller.